__author__ = 'gongwenwei'
import cgi
import os
import datetime
import urllib
import wsgiref.handlers

from google.appengine.ext import db
from google.appengine.api import users
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
from google.appengine.ext.webapp import template

class Greeting(db.Model):
  """Models an individual Guestbook entry with an author, content, and date."""
  author = db.UserProperty()
  content = db.StringProperty(multiline=True)
  date = db.DateTimeProperty(auto_now_add=True)


def guestbook_key(guestbook_name=None):
  """Constructs a datastore key for a Guestbook entity with guestbook_name."""
  return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')


class MainPage(webapp.RequestHandler):
  def get(self):
        guestbook_name=self.request.get('guestbook_name')
        greetings_query = Greeting.all().ancestor(
            guestbook_key(guestbook_name)).order('-date')
        greetings = greetings_query.fetch(10)

        if users.get_current_user():
            url = users.create_logout_url(self.request.uri)
            url_linktext = 'Logout'
        else:
            url = users.create_login_url(self.request.uri)
            url_linktext = 'Login'

        template_values = {
            'greetings': greetings,
            'url': url,
            'url_linktext': url_linktext,
        }

        path = os.path.join(os.path.dirname(__file__), 'index.html')
        self.response.out.write(template.render(path, template_values))


class Guestbook(webapp.RequestHandler):
  def post(self):
    # We set the same parent key on the 'Greeting' to ensure each greeting is in
    # the same entity group. Queries across the single entity group will be
    # consistent. However, the write rate to a single entity group should
    # be limited to ~1/second.
    guestbook_name = self.request.get('guestbook_name')
    greeting = Greeting(parent=guestbook_key(guestbook_name))

    if users.get_current_user():
      greeting.author = users.get_current_user()

    greeting.content = self.request.get('content')
    greeting.put()
    self.redirect('/?' + urllib.urlencode({'guestbook_name': guestbook_name}))

application = webapp.WSGIApplication(
                                     [('/', MainPage),
                                      ('/sign', Guestbook)],
                                     debug=True)

def main():
    run_wsgi_app(application)

if __name__ == "__main__":
    main()